Passenger car equivalents for urban roads using average time headway of car following conditions

Abstract

Passenger car equivalents are used to calculate capacity and evaluate service level of urban roads. This article uses the average time headway of different car following conditions to replace the total average time headway of road vehicles, and the proportion of large vehicles to improve the headway method. This article analyzes the influence of several factors such as the proportion of large vehicles, road attributes, and traffic flow on passenger car equivalents, and obtains the following conclusions: (1) the behavior of vehicles crossing the opposite lanes has an important influence on the passenger car equivalents of the road; (2) passenger car equivalents of vertical sections at the center of central isolation belt are different from those at the start of the road; (3) the road attributes affect the passenger car equivalents; and (4) the passenger car equivalents of heavy vehicles on roads that allow two-way crossover are less than the specific value, however, the passenger car equivalents of heavy vehicles in the road segment without two-way crossing-line are greater than the specific value.